This invention relates to an improved fluidized patient support system that is of particular advantage to burn patients, as well as other patients who are immobilized for extended recuperative periods.
Historically, hospital beds for patients have in general been conventional where, though adjustable as to height and attitude, a mattress-springs arrangement has been provided for receiving the patient thereon covered, of course, with appropriate bed clothing. Particular problems have developed in use of the conventional hospital beds where the patients, due to prolonged contact with the support surface in generally immobile conditions, have developed decubitus ulcers or bed sores, as a result of pressure points between the support surface and certain portions of the patient's body. Additionally, in the case of burn patients where the severity of the injury or wound was such that the patient was affected over a significant portion of his body, the conventional bed presented problems not only with the healing process due to contact between raw areas of the human body and the support, but also due to fluids exuding from the patient's body. In like fashion, other types of injuries and reasons for confinement have presented problems with the conventional hospital bed.
In order to obviate some of the problems inherent with the conventional hospital bed, fluidized patient support structures have been developed as exemplified in the Hargest U.S. Pat. No. 3,428,973, in which a tank is provided, partially filled with a mass of granular material which is received atop a diffuser surface and is covered with a loose fitting flexible patient contact sheet or surface. Fluid, such as air, is forced through the diffuser and fluidizes the granular material, preferably ceramic spheres, with adequate force that a patient received on the flexible sheet is suspended on the fluidized bed. In this fashion, very gentle forces are imparted to the body portions of the patient, whereby the incidence of development of decubitus ulcers is reduced and whereby an individual experiencing trauma, such as produced by severe burns may rest comfortably. In similar fashion, a further fluidized patient support structure is disclosed in the Hargest U.S. Pat. No. 3,866,606 which structure has the same basic elements of that mentioned above with the addition of control means to cyclically fluidize the granular material, also preferably ceramic spheres, for floatation of the patient, whereby in a non-fluidized state, the patient settles into the mass of granular materials which becomes a rigid body contoured structure against which the patient's body may be placed in traction. In like fashion, the cyclic effect of fluidizing-rigidifying the mass of granular material permits variation in patient attitude, again towards the reduction of the incidence of development of decubitus ulcers.
In both of the fluidized patient support systems described above, there is in use of ceramic spheres, for an adult patient, generally a minimum depth of about 12 inches of fluidized granular material located above the diffuser board to preclude any contact between the body of the patient and the diffuser board when the patient is in a sitting position on the bed. In particular, when a patient is attempting to get out of the support structure, and does so by assuming a sitting position, there is of course a greater amount of weight in a concentrated area, such that with less than the 12 inch minimum of granular material or thereabouts, the buttocks of the patient could sink through the material, leaving only a cover sheet above the diffuser board, thereby creating a high pressure point. For support systems for children, or an adult patient which will remain in a supine position, a lesser minimum depth of granular materials is required. Additionally, in a commercial embodiment of the fluidized adult support surface, a quantity of approximately 1,600 pounds of ceramic spheres is employed, thus necessitating significant size and strength for the supporting framework of the fluidized structure to achieve the intended purposes. A total bed weight of approximately 2,200 pounds results, with the side walls of the structure extending above the diffuser board being dictated by the minimum depth requirements. In like fashion, due to the great weight of the overall structure, the supporting framework of course must be suitable for maintaining same. These and other requirements of the present commercial structures thus limit the use of the same due to expense, structural design limitations, size, and the like. Still further, with the commercially available structures, though same are particularly efficacious, use is restricted, especially outside of specialized hospital treatment areas.
Further with respect to the fluidized patient support structure mentioned above, the diffuser board in commercial use is a particle board having a generally uniform porosity thereacross where the porosities are sized at approximately 5 microns to permit the passage of fluid therethrough while at the same time precluding the passage of the ceramic microspheres or other granular material.
The improved structure of the prersent invention will perform at efficacy levels equal to that of the presently commercial fluidized patient support systems, while at the same time, avoiding the problems or structural requirements for same as outlined above. As such, the fluidized patient support structure of the present invention represents a smaller, less costly, lighter, and more versatile patient support structure, the maintenance requirements for which are significantly less stringent.